The answer to this question would be quite long and technical. Here I’ll give just a few short hints.
“Of all the gopīs, Rādhārāṇī is the dearmost. Similarly, the lake known as Rādhā-kuṇḍa is very dear to the Lord because it is very dear to Śrīmatī Rādhārāṇī.
“ ‘Just as Śrīmatī Rādhārāṇī is most dear to Lord Kṛṣṇa, so Her lake, known as Rādhā-kuṇḍa, is also very dear to Him. Of all the gopīs, Śrīmatī Rādhārāṇī is certainly the most beloved.’
“In that lake, Lord Kṛṣṇa and Śrīmatī Rādhārāṇī used to sport daily in the water and have a rāsa dance on the bank.
“Indeed, Lord Kṛṣṇa gives ecstatic love like that of Śrīmatī Rādhārāṇī to whoever bathes in that lake even once in his life.
“The attraction of Rādhā-kuṇḍa is as sweet as that of Śrīmatī Rādhārāṇī. Similarly, the glories of the kuṇḍa [lake] are as great as Śrīmatī Rādhārāṇī’s.
(Caitanya Caritamrita, Madhya-lila 18.7-11)
From this verses we learn that Radhakunda is the utmost sacred place and the most beloved of Radha Krishna.
From other verses we also learn that Sri Caitanya Mahaprabhu offered respectful obeisances to the kundas, setting an example of how we should behave with Them.
Therefore certainly we should bathe in that most sacred tirtha, but we should see Radhakunda as we see the Deities, with deep respect. Just like we don’t jump in the altar and play with the Srimurtis, at the same way we do not play with Radhakunda.
We should never carelessly jump in the water to have fun. Before entering into the waters we should pay obeisances in full devotion, put a few drops of water in our head and then enter chanting the Hare Krishna Mantra and meditating on the Lord’s pastimes.
A few drops it’s the same as doing complete bath. Personally it’s been many years that I don’t enter into the waters and I just put a few drops in my head in meditation.
If someone would say that having fun is exactly what Radha, Krishna and the Gopis do in Radhakunda, my answer would be, we are not Gopis. We are sadhana-bhaktas.
The topic would deserve much more space.
– Manonatha Dasa (ACBSP)